Complex-Shaped Forged Piston Oil Galleries
AssigneeFederal-Mogul Corporation
InventorNorbert G. Schneider
Life of this patent
Estimating the term…
Abstract
A steel piston with an oil gallery, and process for forming a steel piston oil gallery channel, which corresponds to the complex shape of the combustion bowl in the piston crown. The oil gallery channel is first forged to the basic shape that corresponds to the shape of the walls of the combustion bowl. Machine-turning surfaces in the oil gallery channel can be machine-finished as desired. Surfaces in the oil gallery which cannot be machined with conventional turning operations, such as recesses and protrusions into the channel, are left in the original forged condition.
Claims22
A piston comprising:
- a lower member, said lower member comprising sidewall portions and pin bores;
- an upper crown member joined to said lower member, said upper crown member being fabricated of forged steel and having a combustion bowl on an upper side thereof and an oil gallery channel on the lower side thereof, wherein said oil gallery channel includes at least one machine-turned wall surface portion and at least one as-forged non-machined pocket portion, said pocket portion being recessed radially inwardly toward the longitudinal axis of the piston.
The piston as described in claim I wherein a plurality of said recessed non-machined pocket portions are provided, said pocket portions being spaced uniformly circumferentially in said oil gallery channel.
A piston comprising:
- a lower crown;
- an upper crown joined to said lower crown, said upper crown being fabricated of forged steel and having a combustion bowl on an upper side thereof and an oil gallery channel on a lower side thereof, wherein said oil gallery channel includes a machine-turned wall surface portion in combination with at least one non-machined, as-forged pocket portion that is recessed relative to said machine-turned surface.
A piston for an internal combustion engine, comprising:
- a steel piston crown member having a complex shaped combustion bowl;
- an oil gallery channel in the piston crown member having a shape corresponding to the complex shape of the combustion bowl, said shape of the oil gallery channel being formed by forging;
- and
- a lower piston member attached to said piston crown member, said lower piston member having sidewall members and pin bores.
The piston as described in claim 47 wherein forged surfaces which cannot be machined by conventional machine-turning operations are not machined and are left in the forged condition.
A method for forming an oil gallery channel in a steel piston crown member, said method comprising the steps of:
- providing a piston crown member made of a steel material;
- forming a complex shaped combustion bowl in the upper surface of said piston crown member by a forging operation;
- and
- forming a complex shaped oil gallery channel in the lower surface of said piston crown member by a forging operation, the shape of the oil gallery channel corresponding to the complex shape of the combustion bowl.
Dependencies are inferred from the claim text.